Automatic landing control for aeroplanes



OctZ1,1930. 'w,'L o 1,779,168

AUTOMATIC LANDING CONTROL JFOR AEROPLANES Filed May. 15, 1929 I" GAMKQ ATTORNEY Patented Oct. 21, 1930 UNITED :STATES PATENT OFFICE WALTER L. ISOH, OF GROWS LANDING CALIFORNIA, ASSIGNOR OF I'OR'JJY PER CENT TO EDWARD LISOTA, OF SAN FRANCISCO, CALIFORNIA AUTOMATIC LANDING CONTROL FOR AEQOPLANES Application filed Iay- 15,

This invention relates to aeroplanes and,

particularlyto a device for facilitating landing. Vhen an aeroplane approaches the landing field it frequently descends at such an angle to the ground that there is grave danger of the aeroplane nosing into the ground and turning over unlessthe elevator is actuated by the pilot at just the right instant and to the proper extent to offset the downward angle of the plane. Experienced pilots usually are able to properly time the movement of the elevator soas to effect a proper landing but student or amateur pilots frequently crash owing to the failure to use the good judgment necessary under the circumstances. Also when landing in the dark even competent dots are apt to misjudge their distance f rom the ground with distastrous results.

It is also sometimes necessary for the pilot to abandon the plane while in midair, and take to the parachute, leaving the plane to glide down of itself, balanced at such an angle by the stabilizers as will allow it ,to properly glide toearth, but which will cause it tocrash upon contacting with the ground.

The principal object of my invention is to provide a device by means of which the eleva tor of the plane will be automatically turned to elevate the nose of the plane at just the rightmoment so that the aeroplane will assume the desired horizontal position upon reaching the ground, and regardless of the action of the pilot, or of his absence from the plane in certain cases. Accidents due to faulty udgment and control, or entire lack of control, as above outlined, will therefore be largely lessened if not entirely eliminated.

A further object of the invention is to provide a device for the purpose, the actuating member of which may be placed in operative or non-operative positions, or readily disconnected from the elevator at the option of the pilot, in the event he does not desire or need 1 the aid of the automatic functioning device.

A further object of the inventionv is to produce asimple and inexpensive device and yet one which will be exceedingly effective for the urpose for which it is designed.

T ese objects I accomplish by means of such structure and relative arrangement of parts 1829. Serial No. 363,380.

partly broken out showing my landing control I attachment applied thereto and initially functiolzing with the approach of the aeroplane to ear 1. V v

Fig. 2 is a similarview showing the position of the control device after it has completed its elevator actuating movement.

Fig. 3 is an enlarged fragmentary side elevation of the connection means between the elevator and the actuating arm.

Fig. 4 is a side elevation of the control device showing a modified manner of connecting the same to the elevator.

Referring now more particularly to the characters of reference on the drawings and particularly at present to Figs. 1 tov3" the numeral 1 denotes the fuselage of any ordinary aeroplane havingthe usual elevator 2 at the back arranged for movement in a vertical plane and manually controlled from the stick or lever 3 disposed in the pilots cockpit of the plane, and connected to the elevator the fuselage centrally of its width and preferably adjacent the lever is an arm whichpis pivoted intermediate its ends at the bottom of the fuselage so as to have a relatively short portion above thepivot and along portion below. The portion below the pivot or which depends below the body is of such length that when projecting substantially at right angles to the fuselage its lower end will be some distance below a line L projected from the bottom of the front landing wheels 5 to the tail-skid 6. By reason of this arrangement the arm will obviously engage the ground and tend to move rearwardly, before the wheels engage the ground. A snap action spring 7 is secured at its lowerend to the arm below its pivot and at its upper end to' the fuselage in such relation to said pivot as to tend to maintain the arm either in a fully depressed position, as shown in'Fig. 1, or in bove movement of the arm To cause the a from a depending to a folded position to regardless of the move the elevator up manipulation of the same by the pilot, a connecting unit U extends from the upper end of the arm to the upper elevator control arm 9.

This unit comprises a sna hook 10 or other member which may be readi y and detachably applied to any one of a number of holes 11 in the upper portion of the arm, a turnbuckle 12, a tension spring 13, and a length of wire or cable 14. The turnbuckle of course enables the tension of the spring to be altered while the row of holes 11 enables the elevator pulling unit to be connected to the arm so as to move the elevator different distances with the same extent of movement of the arm as may be desired. The provision of the spring in the elevator control line rovides an automatic equalization in position of the elevator with regard to the air pressure, which is governed by the speed at which the plane approaches the ground.

In operation for instance almost as soon as the arm enga es the ground it will be thrown back to its fu ly folded position by reason of the initial frictional engagement of the arm with the ground and the subsequent pulling action of the spring 7. The elevator Wlll therefore be raised to its fullest extent as far as the functioning of the arm is concerned. If the speed of the aeroplane isvconsiderable such extent of raising of the elevator might cause the plane to again rise in the air. The relativel great air pressure then pressing against t e elevator however has a tendency to depress the same. This depression is actually eflected by reason of the spring 13, which yields and len hens the unit U to an extent depending on t e comparative strength of the air pressure and spring. The snap act on 5 ring prevents this pressure from lowering tlie arm and thus destroying the tendency of the elevator to remain raised. If the speed of the machine as it approaches the ground is relatively slow or as the speed decreases as the plane moves along the ground, the air pressure on the elevator is lessened and the angle of the same gradually increases as the resistance to the spring 13 is less. Thus the angle of the elevator becomes automatically set according to what the conditions demand, since it is obvious that for different speeds different elevator settings are necessary to accomplish the same result, and the greater the speed the less should be the angularity of the elevator.

In the above showing the arm is connected direct to the elevator independent of the manual control wires. In the arrangement shown in Fig. 4 the unit U is shorter and extends only from the upper end of the arm 4: to the swing arm 15 which is connected to the control lever 3 and from which the wires 16 extend to the elevator.

In either case the upper end of the actuating arm is positioned so as to be convenient for the pilot to couple or uncouple the snap hook of the pull unit. The coupling feature is desirable since it may be desired to retain the control arm folded when in actual flight, without the elevator being turned upwardly or without the action of the spring 13 having to be constantly oilset by a pull on the manually controlled lever.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. In an aeroplane, an elevator, an arm pivoted on and depending from the aeroplane to be engaged by the ground and moved rearwardly, connection means between the arm and elevator to pull the latter to an elevating position when the arm is thus moved rearwardly and a snap-action spring mounted in connection with the arm tending to hold the arm both in depending and rearwardly moved positions.

2. In an aeroplane, an elevator, an arm pivoted on and depending from the aeroplane to be engaged by the ground and moved rearwardly, connection means between the arm and elevator to move the latter to an elevating position when the arm is thus moved rearwardly, and means resisting return movement of the arm to a depending position after it has once been moved rearwardly a predetermined extent.

3. In an aeroplane, an elevator, an arm pivoted on and depending from the aeroplane to be engaged by the ground and moved rearwardly, connection means between the arm and e evator to move the latter to an elevating position when the arm is thus moved rearwardly, and means acting on the arm to move the same to its rearward limit after it has been once swung rearwardly by engagement with the ground throu h a certain are.

t. In an aeroplane, an e evator, an arm pivoted on and depending from the aeroplane to be engaged by the ground and moved rearwardly, connection means between the arm and elevator to move the latter to an elevating position when the arm is thus moved rearwardly, said means including a member for detachable coupling with the arm, and means enabling the arm to be held in a rearward and substantially horizontal position against the fuselage of the aeroplane when said member is uncoupled from the arm.

5. In an aero lane, an elevator, an arm pivoted interme iate its ends on the aeroplane and depending from the fuselage to be engaged by t e ground and moved rearwardl t e upper end of the arm pro'ecting into the cockpit of the fuselage, an a connection between the upper end of the arm and the elevator to pull the latter upwardly with the rearward movement of the arm; said connection including a hook adapted for detachable coupling with the upper end of the arm.

In testimony whereof I afiix In si nature.

WALTER 'I OM. 

